Genetic Diversity and Population Structure of Corylus yunnanensis (Franch.) A. Camus Using Microsatellite Markers in Sichuan Province

Abstract

Corylus yunnanensis (Franch.) A. Camus is a deciduous shrub, native to the Hengduan Mountain of Qinghai–Tibetan Plateau, and is an economically and ecologically important woody crop species. In the present study, one hundred and fifty trees sampled from ten populations of C. yunnanensis in Sichuan Province were investigated to assess the population genetic variation using nine SSR markers. The results revealed that C. yunnanensis has an average value of 12.111 alleles, 3.376 effective alleles, an expected heterozygosity of 0.648, and an observed heterozygosity of 0.630, presenting a relatively high level of genetic diversity. The C. yunnanensis populations in Maoxian and Wenchuan of Aba Prefecture expressed the highest value of genetic diversity, whereas the Hanyuan and Muli populations showed the lowest. Moreover, the genetic differentiation of ten C. yunnanensis populations averaged to 0.106. Correspondingly, AMOVA revealed that 87% of the total variance was accounted for the variation within populations, and only 13% was among the populations. Both UPGMA and Bayesian STRUCTURE clustering suggested that the ten C. yunnanensis populations could fall into three clusters: the Aba Prefecture population, the Ya’an population, and the population of Ganzi and Liangshan Prefecture, indicating a significant geographic distribution, which was also confirmed by the Mantel test. Our study could provide a better understanding of population genetic diversity, and serve valuable information for the genetic improvement of C. yunnanensis.